The present invention relates to suspension of tubes and pipes conducting hot fluids such as steam.
Suspensions of the type to which the invention pertains are, for example, needed in power plants. It is required that the suspension force exerted upon the tube or pipe is and remains constant, even if the point of suspension of the tube is displaced relative to a true stationary point in the building, frame, foundation or the like from which the tube or pipe is suspended, the displacement being the result of thermal expansion of the tube.
The German Patent No. 1,159,710, particularly FIG. 5 thereof, discloses a suspension for a tube attempting to meet the above-mentioned requirement, wherein a follow-up type feedback controller, including an electric motor operating a spindle, is provided to adjust the spacing between two points of suspension on frame and tube, so that the force of suspension does not vary significantly. This control device is particularly provided to compensate temperature dependent displacements of the tube side point of suspension. Any change in the suspension force generally is effective as a change (increase) in tension in the tube or pipe. It is obvious that this type of suspension is very elaborate and will fail, for example, upon electric power failure.
This known suspension reacts against vibrations of the tube or against earthquakes just as if it were completely rigid, which is a desirable feature but contrasts with resilient or other suspensions, also capable of taking up thermal expansion but failing to resist adequately rigidly to other external forces.